Conventional razor blades with a cutting edge linearly formed along a side of a thin steel sheet may accidentally cause injury to skin in use. Therefore, it is a major task to improve the safety. For example, it has been proposed to reduce the damage to the skin by winding a plurality of thin wires around the razor blade at regular intervals. However, from the viewpoint of improving the safety, while maintaining excellent cutting performance for an object to be cut such as beard and hair, a satisfactory level has not been always achieved.
In addition, various kinds of net blades have been proposed to achieve a further improvement in safety. For example, such net blades are disclosed in U.S. Pat. No. 4,875,288 and European Patent No. 0 541 723 B1. In the case of a net blade made of a metal material, however, since its cutting edge is formed by machining, there is a limitation with respect to the formation of the cutting edge with a small nose radius. For example, even when burrs generated at the cutting edge by grinding are removed by precise polishing such as lapping, it is difficult to obtain a nose radius of 1 μm or less. Due to this reason, it has not been achieved yet to smoothly shave beard or hair by the net blade made of a stainless steel except for a razor blade with a linear cutting edge of a nose radius of approximately 0.1 μm, which is obtained by grinding a stainless steel sheet. Moreover, in the conventional razor blades on the market, a technique of forming the cutting edge of a nose radius of 0.1 μm or less has not been sufficiently established yet.